The Special Studies Institutional Review Board (SSIRB) was established by the National Cancer Institute (NCI), National Institutes of Health (NIH) in 1992 under the authority of NIH Multiple Project Assurance (MPA), in response to increasing concerns regarding the protection of persons participating in research projects directed by the NCI. The increase in the number of NCI protocols requiring IRB review, particularly in non-clinical (non-therapeutic) research areas, led to the formation of the NCI SSIRB as a second NCI IRB, with the mandate to review research protocols involving human subjects conducted by NCI scientists and staff through facilities other than those of the NIH Clinical Center. Traditionally, most of these projects have focused on special areas of applied science, such as cancer epidemiology, surveillance, prevention and control, behavioral work and social aspects of cancer and health services research. In recent years, the scope of reviewed research has expanded to include molecular and genetic studies relating to cancer epidemiology, risk assessment, prevention and control, psychosocial and behavioral interventions, and ethical policy issues. Currently there are on average about 170 studies under review.